This was really cool!! Like Velvet I can tell there's a lot of depth, and it's already very fun and rewarding. Having real orbital dynamics is super awesome and can lead to very fun outcomes if explored further! And it's awesome that this is open source!
I've got a big ol list below of what is (I hope) constructive criticism. Hope it helps!
1. The UI is super cluttered and not very thought out. It really needs to be whittled down to the bare minimum.
- Text and buttons also overlap on my screen, so it clearly needs to be tested in a greater variety of resolutions. The tutorial text spills down over the bottom of the screen.
- I just got lucky clicking on J to open the journal because there was no indication of what that button does. Have tooltips for your buttons.
- Clicking the UI sometimes triggers thrusters and shooting. Maybe just lock input if you're docked in a station and have a button to leave? This could also allow keyboard navigation.
- Massive information overload when first starting. The tutorial is a big wall of text for what is really quite simple information. Instead of telling the player not to press anything, just stop them from being able to. Don't have all the UI visible at once, just make them appear piece by piece as they become relevant. Maybe start off with teaching combat (the fun part) in a more controlled enclosed arena of some kind before letting players out into open space?
- Maybe replace more of the bland text with icons that the player can get used to by hovering?
2. Gameplay impressions in first minutes:
- Tapping thrust is annoying, I wanna hold the mouse down.
- Targeting is super hard to control, it seems to just randomly pick nearby targets if they're off screen, and I can't really tell which direction they are.
- Most of the exposition from the characters besides the really important stuff is pretty unnecessary and could be told through tooltips and flavour text. The fact I have to wade through so much text to find the controls and core concepts is kinda tedious.
3. Bugs
- At some point my thrust and shoot buttons flipped? Not sure if that's a bug or an option somewhere?
- It says you cycle between boosters with B and fire with G but actually you just fire with B
4. I won't comment much on the graphics because obviously they have a lot to be desired and I guess you have plans to make it pop a little more. The only thing I will say is the main challenge will be differentiating between all the different objects. Silhouettes are gonna be very important :)
Overall it's a fantastic base for a game and has a lot of potential. I hope you see it through!